Process for the manufacture of crimped spun yarn



June 23, 1970 HIROSHI NAKANO' ETA!- 3,516,241

PROCESS FOR THE MANUFACTURE OF CRIMPED SPUN YARN Filed Oct. 25, 1968 2 Sheets-Sheet 1 United States Patent 3,516,241 PROCESS FOR THE MANUFACTURE OF CRIMPED SPUN YARN Hiroshi Nakano, Fuji-ski, Hideo Takai, Numazu-shi, and Yoshiaki Murono and Fumio Nakajima, Fuji-shi, Japan, assignors to Asahi Kasei Kogyo Kabushiki Kaisha, Osaka, Japan, a corporation of Japan Filed Oct. 25, 1968, Ser. No. 770,687

Int. (:1. D02g 1/12 US. Cl. 57-457 Claims ABSTRACT OF THE DISCLOSURE Multifilaments are introduced. into a draft zone spinning stage, thereby draft cutting the filaments into cut fibers consisting of a substantially parallel fibers assembly. Alternately, a roving of staple fibers is introduced into a spinning frame stage for providing cut fibers of a substantially parallel fiber assembly, and then the latter is fed forcibly into a stuflingly crimping zone for providing crimps and heat setting the latter, and the thus crimped fibrous material is wound up while being twisted.

By this process, crimped spun yarn is obtained which is characterized by superior bulkiness and crimp tensional resiliency.

This invention relates to process for the preparation of crimped spun yarn from either multifilaments or staple fibers of a thermosynthetic substance, preferably polyamide such as nylon.

It is the main object of the invention to provide a process for the manufacture of the crimped, tensile resilient fibrous yarn of the above kind from relatively high denier multifilaments or staple fibers, where the products will compare favorably with conventional fine diener multifilament crimped yarns, polyester or the like.

It has already been proposed to produce crimped yarns from continuous multifilaments by crimping and twisting. It is however well known that once crimped, filaments are very difiicult to spin because considerable troubles are encountered by the very existence of the artificially and intentionally provided crimps. Therefore, in order to attain trouble-free spinning of the crimped filaments, it is necessary to reduce the crimping degree which will in turn reduce among other features, the desired bulkiness and tensile resistance of the products. Another difficulty resides in the frequently encountered hitching which means that when a constituent continuous filament is hooked off or drawn out a forced and crimped contraction will occur over a wide area of the textile fabric which is woven or knitted from these continuous crimped filaments.

Therefore, the yarn must preferably be composed of cut fibers.

It has been also proposed to prepare crimped yarns I from staple fibers. In this case, crimps are formed on the fibrous material in the form of fibrous mass, carded webs or slivers. Therefore, this kind of crimped fibrous material should be newly spun and thus the aforementioned difiiculty of spinning is again experienced. Generally speaking, the crimped linear products from staple fibers are inferior in their tensional modulus to those which have been manufactured from continuous multifilaments.

A still other object of the present invention is to obviate the aforementioned various drawbacks inherent in the conventional process for the manufacture of crimped bulky yarns.

These and further objects, features and advantages will become more clear from the following detailed descripice tion by reference to the accompanying drawings which constitute part of the present specification, and with several numerical examples to be set forth hereinafter.

In the drawings:

FIG. 1 is a schematic representation of a manufacturing plant which is adapted for use in carrying out the process according to this invention, using as the synthetic thermosetting fibrous material continuous filaments preferably in the form of tows.

FIG. 2 is an enlarged axially sectional view for means for use in the stufiingly crimping and reserving stages of the process according to the invention.

FIG. 3 is a perspective view of the mechanism shown in FIG. 2.

FIG. 4 is an enlarged perspective view of a part of the plant shown in FIG. 1, showing a decrimping and tension compensating means.

FIG. 5 is a similar view to FIG. 4, where the shown mechanism is in its stage for compensation of yarn tension which has been lost by the detangling operation of the mechanism when, for instance, a tangled yarn mass is being straightened out at the inlet.

FIG. 6 is an explanatory schematic view of part of means adapted for performing a modified process, giving a possibility for manufacturing same kind of improved crimped products from staple fibers.

FIG. 7 is a diagram showing the results of comparative tests for the crimped bulky yarns manufactured by the inventive process relative to control yarns.

Referring to FIG. 1, a continuous bundle of polyamide, polyester or the like multifilaments 10 is withdrawn substantially in parallel filament arrangement from package 11, passes through a pigtail guide 12, and is then passed in multiplie and parallel wraps about a series of positively driven rollers 13, 14 and 15 in succession, said rollers constituting a roller group defining a preparatory feeding stage to the leading or back end of a stretch break zone beginning at a stationary thread guide 60 and terminating into a pair of rollers 17 and 18, followed by a main drafting zone constituted by a pair of moving apron bands 21 and 22, preferably of leather.

In one embodiment of the invention, not shown, the multifilaments bundle 10 is supplied to guide 12 directly from a spinning machine rather than from a package.

Having been delivered from the feed roller groups 13-15, the bundle 10 is fed through carrier or break roller 16 to between rotating top roller 17 and endless apron band 22, the latter being positively driven by drive roller 18 which is kept in engagement with said top roller 17 through the intermediary of said band 22. The filaments bundle 10 is further conveyed forwards by being caught between the pair of apron bands 21 and 22, the former being driven by drive roller 19. The delivery ends of these bands are guided respectively by stationary guide members or aprons 23 and 24. Bottom apron band 24 is guided positively further by guide roller 20.

The thus delivered filaments at 25 from the main drafting zone, having been drafted and random fiber cut, yet parallel maintaining the bundle shape as before, are then conveyed to an auxiliary or after-drafting zone extending between two pairs of positively driven rollers 26, 27 and 28, 29, so as to provide the cut fiber bundle at 25 with a slight drafting effect such as or so.

The thus drafted fiber bundle delivered from the delivery roller pair is fed forcibly to the stuffing box assembly, generally shown at 30 and more specifically shown in FIGS. 2 and 3 in an enlarged representation. The stuffing box or stuifer having a rectangular cross-section as shown in FIG. 3 is formed with a longitudinal bore 31 in which the fiber bundle is forced into a zigzag stack,

said bore being opened at its beginning end directly to the delivery side of the mutually engaging and rotating delivery rollers 28, 29. The thus forcibly fed fiber bundle is in its continuous state as a whole, although each of the constituent filaments has been cut into short lengths of approximately 100 mm. or so, in the fiber form. As seen from the drawing, the forcibly fed fiber bundle at 32 represents primary fine crimps and secondary coarse crimps as found in the stuffer bore 31 which crimps are set therein under the influence of heat energy supplied by heating means preferably consisting of electric heating elements 33 embedded in insulator layer 34 such as asbestos and connected to a suitable current source as schematically shown at 35. The insulator layer 34 is armoured by a metallic cylinder cover 36 for increasing its rigidity.

The stuffer chamber 31 is normally closed at its outlet end by a pivotable closure plate 31a, but in operation kept in communication through the forcibly opened closure with a channel-shaped chute 37 which is rigidly connected with the stufler 30 and provided with a plurality of, herein shown three, pressurizing means formed in this case into pendulum plates 38, each carrying a weight mass 38a. The crimped and heat set fibers 32a are taken out forcibly against the gravity checking action provided by the pendulum means 38, as most clearly seen from FIG. 2, and fed to decrimper, generally shown at 39.

The fiber bundle 32a is threaded through stationary yarn guide eye 41, and then brought into contact alternately with stationary guide bar 40 and the guide arms 42a and 42b of pivotable tension bar 42. Then, the bundle is threaded through second stationary yarn guide eye 45, thence in a Zigzag way through a plurality of parallel yarn guide pins 46. The tension bar 42 is pivotably mounted at 43 and weighted at 44. The weight mass is shown at 49. Yarn guides 46 extend from the vertical wall part 39a of the decrimper 39.

The fiber bundle 32]), which has been considerably, yet provisionally decrimped in the decrimper 39 and yarn guide pins 46 as will be more fully described hereinbelow, is passed between a pair of positively driven rollers 47 and 48 the rotational speed thereof being so selected bundle such as a 1l0%200% or so during passage therebundle 32b by shifting the relative phase of the constituent of between weight mass 38 and for shaping the fiber as to provide a certain amount of stretching to the fiber cut fibers.

In FIG. 4, there is shown a yarn tangle 71 caught by the first eye 42. When the yarn tangle is suddenly detangled, the fiber bundle at 32b will lose its tension. In this case, the weight mass 49 will act upon the tension bar 42 which will swivel in the clockwise direction, thus shifting from the position shown in FIG. 4 to that shown in FIG. 5. In this way, occasionally encountered loss of yarn tension can be effectively compensated, as is clearly understood by review of FIG. 5.

The fiber bundle 32c thus provisionally decrimped is threaded under a loosened condition through snail wire 59 and then twisted by means of ring 50, traveller 51 and spindle or cop 52 which are normally employed in conventional ring spinning frame although such twister can be replaced by any other known twisting mechanism. The weight mass 49 is preferably selected to g. per denier of the yarn under treatment.

In a modified arrangement shown in FIG. 6, the numeral 61 denotes a package from which is drawn out a roving 62 of staple fibers through a pigtail guide 63 and fed to a pair of positively driven back rollers 64 and 65 initiating a drafting zone terminating into a pair of mutually cooperating apron bands 21 and 22' corresponding to those shown at 21 and 22, respectively in, FIG. 1. Rollers 17', 18' and 20' having similar arrangement and function to those shown at 17, 18 and 20 guide and drive respective aprons 23' and 24 similar to those at 23 and 24in FIG. 1.

The thus drafted roving 62a delivered from the apron band assembly is then further treated as in the case of FIG. 1, thus no further details being necessary for clear understanding of the present embodiment.

For carrying out the inventive process, the provision of a cooling zone is provided by the chute 37 which is made of a metallic material such as steel, copper, brass or the like. Therefore, the crimped and heat set filament bundle or fleece delivered from the stufler box 30 and stays for several minutes until it is effectively cooled to approximately 50 C. Although not shown, fan cooling appliances may be provided for accelerating this cooling effect. If, on the contrary, a hot fleece is subjected to a provisional decrimping stage, the once heat set crimps may be considerably lost and the desirous crimp effect will be substantially injured.

In the following, several numerical examples will be given for better understanding of the process according to this invention.

The provision of the provisionary decrimping zone formed by the decrimper 3-9 and thread guide pins 40 is also critical for carrying out the inventive process. If this zone should be omitted, the twisting efficiency will be considerably lowered by the very existence of too much crimps. Upon practice of the inventive process, the provisionarily smoothed-out crimps will naturally be recovered upon having been bobbined.

EXAMPLE 1 A bundle of 3000 nylon monofilaments oriented, each 3 denier, was introduced in the manner described hereinbefore into the stretch break zone 13-18 and treated so as to be subjected to a random fiber cutting under stretching amounting to 358%. Then, the thus fiber-Cut and stretched tow was further drafted at 17-27 composing the front or main drafting zone to 74% length so as to provide a fleece, 225 denier. This fleece was subjected to a slight stretching of 102% at 26-29, and forcedly delivered from the last delivery roller pair, having 4 mm. roller length, into stufiing box 30 which was kept at -1-60 C. so as to provide primary and secondary crimps, thence further into chute 37, for effective cooling, from which the crimped fleece is fed to decrimper 39 where the fibrous material was subjected to a fiber phase shift to a certain degree. Then, the material was twisted 350 turns per meter at 47-52 which are shown equally in FIG. 1.

The thus crimped spun bulky yarn showed a crimp elongation rate 55-60% which means a remarkable result in the art.

EXAMPLE 2 Two bulky and twisted yarns prepared on the apparatus shown in FIG. 1 and processed in the same conditions referred to in the foregoing Example 1, where combined into a twin strand or two ply thread by tvw'sting the strands at and 350 turns per meter, respectively. The resulted thread represented a highly intensified bulkiness and showed a crimp elongation rate of 60-80%. This bulky thread was introduced into a channel-shaped receiver and stacked in loose state in the same direction and in parallel. When a load of 200 g./.16 cm. was applied to the stacked thread mass, the latter ShOlWCd a specific volume of 14.2 cm. /gr. which means a highly improved bulkiness.

j EXAMPLE 3 An oriented tow of 6000 denier Tetron or polyester monofilaments, each 3 denier, was introduced in the manner described hereinbefore into the stretch brealk zone system spinning mechanism 13-18 under a draft of 358% treated so as to be subjected to a random fiber cut. Then, the stretched and fiber cut tow was further drafted at 17-27 composing the main drafting zone to an overall length of 74% so as to provide a fleece, 225 denier. This fleece was subjected to a stretching of 108% at 26-29, and forcedly delivered from the last delivery roller pair,

having 4 mm. roller length, into stufling box 30 which was kept at 140 C. so as to provide primary and secondary crirnps, thence further into chute 37 from which the crimped fleece is fed to decrimper 39 where the fibrous Comparative tests were carried out between the crimped spun yarns in accordance with the inventive process and conventional comparative products, as shown in the following Table II.

TABLE II Control Improved Specimens Specimens (Ill) Tenacity (g) 43 791 326 730 359 753 Elongatlon (percent) 35. 5 54. 29. 32. 3 23. 5 2. 26 Coetf. of var ation (percent) 14.0 8.1 13. 9 10. 2 16. 7 20. 5 Apparent thickness (mm) 0. 65 0. 976 0.60 0.87 0. 46 0. 89 Bulk ness (cub. cm. per gr.) 10. 8 14. 2 10. 4 13. 0 7. 2 8.3 Tensl onal modulus (percent) 58. 5 67. 5 4S. 0 57. 0 25. 1 31. 9 Elastic recovery (percent) 94. 8 97. 5 91. 0 93. O 72. 8 77. 5

Crimp tests:

Number of cr mps per mm. 60. 1 59.0 43.1 Percentage crimps (percent)- 42. 7 45. 4 36. 3 Crimp elastlcity (percent) 63. 7 66. 3 61. 9

material was subjected to a fiber phase shift to a certain degree. Then, the material was twisted 350 turns per meter at 47-52 which are shown equally in FIG. 1.

The thus crimped spun bulky yarn showed a crimp elongation rate 48% which means a remarkable result in the art.

EXAMPLE 4 Two bulky and twisted yarns prepared on the apparatus shown in FIG. 1 and processed in the same conditions referred to in the foregoing Example 1, where combined into a twin strand thread by twisting the strands at 190 and 350 turns per meter, respectively. The resulted thread showed a highly intensified bulkiness and represented a crimp elongation rate of 67.5%. This bulky thread was introduced into a channel-shaped receiver and stacked in loose state in the same direction and in parallel. When a load of 200 g./ 16 cm. was applied to the stacked thread mass, the latter showed a specific volume of 13.0 cm. gr. which means a highly improved bulkiness. See also FIG. 7.

EXAMPLE 5 A roving, 0.3 gr./m., was prepared through a conventional spinning process, so as to comprise nylon staple fibers, having a mean length of 89 mm. Each of the fibers was of 3 denier.

The roving was then subjected to a stretch break at 13-18 in FIG. 1 as before under a draft of 115% and to a substantial draft of 1,045% at 19-27, to an additional and slight draft of 108% at 26-28, thereby providing a fleece of 225 denier. This fleece was fed from the roller pair 28, 29, each having a 4 mm.-length, into the stufiing box 30, the wall temperature of which was kept at 130 C. The thus crimped and heat-set fleece was treated further as before. The twisting was .given at 350 turns per meter. The testing results of this twisted yarn are enlisted in the following Table I.

Remarks:

Stuffing box temperature=120 C. I=Nyl0n crimped spun yarn. II=Tetron crimped spun yarn. III=Woollie nylon cut fiber yarn. l=Kind of yarn. 2=Counts (metric). 3=Twisted yarns per meter. 4=Testing item.

In the above comparative tests, the conventional comparative fibrous products were such that roving of Woollie nylon cut fibers were textured on a spinning frame comprising drafting means and twisting means. In comparison therewith, the improved fibrous materials used in the tests were prepared in such a way that nylon filament tows, 3 denier per fil., overall counts 6,000 denier, not textured, or polyethylene terephthalate filaments, 3 denier per fil., overall counts 6,000 denier, were processed on the crimping and spinning frame shown in FIG. 1.

Values of tensional modulus and elastic recovery enlisted in the above Table II were measured in the following way:

The yarn specimen was fixedly supported at its upper end and an initial load of 2/1000 gr. per denier specified was suspended at the lower end of the specimen. After lapse of 30 seconds, a mark was made given on the specimen just at the distance of 10 cm. which length was denoted :1.

Then, the initial load was replaced by an increased weight of A g. per denier and upon lapse of 30 seconds, measurement was made along the specified linear range terminating in said marked point, the measured length being denoted b. Upon removal the secondary load and after lapse of 2 minutes, the initial load was again suspended and then, after 30 minutes, measurement was made along the above specified range, the measured distance being denoted 0. These measured values were introduced into the following formulae:

tensional modulus (percent) b g a X and elastic recovery (percent) 5:; X 100 that owned by the improved products according to this invention was also substantially doubled over the conventional comparative values. On the other hand, the elastic recovery rate was increased favorably by substantially 30%. It will be further well understood, other various physical natures such as elongation, coefiicient of variation, number of crimps, and the like were also considerably improved.

FIG. 7 illustrates comparative bulkiness curves corresponding to the bulkiness values enlisted in the foregoing Table II, from which the superior results in bulkiness can be clearly ascertained.

In this case, the control yarn Was prepared in such a way that Woollie nylon, 70-denier, 17 filaments Were cut into four lengths of fiber, (A) 128 mm.; (B) 115 mm.; (C) 102 mm. and (D) 89 mm. These cut fibers (A), (B), (C) and (D) were mixed together in equal rates, and then spun on a conventional spinning machine into a continuous monopoly yarn.

Although only a limited number of numerial examples have been given in the foregoing, it should be stressly noted that the example are exclusively for illustrative purpose, and various changes and modifications will easily occur to those skilled in the art upon read through the foregoing description of the present invention.

What we claim is:

1. In a process for the manufacture of bulky and elastic and crimped spun yarn, the improvement which comprises: drafting a fibrous synthetic thermoplastic material comprising substantially parallel-arranged fibrous constituents in a drafting zone, discharging the thus drafted material under compression into a heated stuffing and crimping zone, thereby providing said drafted material with primary and secondary crimps, passing the thus drafted, crimped and heat-set material through a reserve zone for effective cooling, stretching the material taken out from said reserve zone from several percent to 200%, and finally twisting the stretched fibrous material to produce a twisted yarn.

2. Process as set forth in claim 1, wherein advance of passing through said stretching zone said material is passed through a de-crimping tension compensation zone.

3. Process as set forth in claim 1, wherein the crimped and heat-set fibrous material is cooled in the reserve zone to a temperature between 60 C. and room temperature.

4. Process as set forth in claim 1, wherein the starting material is continuous multifilaments.

5. Process as set forth in claim 1, wherein the starting material is a staple fiber roving.

References Cited UNITED STATES PATENTS 2,156,723 5/1939 Esselmann et al 19-.32 XR 2,419,320 4/1947 Lohrke 1932 XR 2,611,931 9/1952 Wilclbolz 19.58 XR 2,784,458 3/1957 Preston l9.58 XR 2,797,444 7/1957 Takagi et al. 19-.35 XR JOHN PETRAKES, Primary Examiner US. Cl. X.R. 

